Phaedra is a poor sponge diver on the lovely Greek isle of Hydra. While diving, she discovers an ancient brass and gold statue of a boy riding a dolphin, which is said to have the magical power to grant wishes. Her shiftless boyfriend wants to sell it to an unscrupulous art collector, but Phaedra wants to give it to anthropologist Jim Calder, who would return it to the Greek government.

Mike and Tony Petrakis are a Greek father and son team who dive for sponges off the coast of Florida. After they are robbed by crooks, Arnold and the Rhys brothers, Mike decides to take his men to the dangerous 12-mile reef to dive for more sponges. Mike suffers a fatal accident when he falls from the reef leaving Tony to carry on the business. But now he has a companion, Gwyneth Rhys.

Greek sponge divers in Tarpon Springs, Florida duel over diving methods and fight over the same girl, and only one will survive.

Documentary film about the adventurous professional life of sponge divers on the Greek Aegean island of Kalymnos. Their existence has been called into question since the entire sponge population became unusable due to fungal infestation in the fall of 1986, for which the fishermen blame the Chernobyl disaster.